The present disclosure generally relates to a vibratory apparatus and, in particular, to vibratory feeders or conveyors capable of transporting objects in a curved path.
Two-way vibratory feeders and conveyors are generally known in the art and have substantial applications in a variety of fields. In foundry operations, for example, castings may be delivered to the feeder or conveyor at a location intermediate its ends and the feeder or conveyor is energized to transport castings to one end or the other depending upon where it is desired to locate the casting.
Some conventional two-way conveyors include an elongated bed with an upwardly facing, generally horizontal, elongated feeding surface. The bed is conventionally supported on isolation springs adjacent to ends of the bed. Two vibration inducing assemblies, which typically will be electric motors with eccentric weights on their output shafts, are secured to the bed generally centrally thereof. Slats at approximately a 45xc2x0 angle connect each of the motors to the bed, with the left most motor slats being canted approximately 45xc2x0 to the left and the right most motor slats being canted approximately 45xc2x0 toward the right, and angularly separated from the left most motor slats by approximately 90xc2x0. In operation, when the left most motor is energized, vibration resulting from eccentric revolution of the associated weight will cause material to be conveyed from right to left. When the other motor is energized, conveying will occur in the opposite direction. The slats typically used in such systems are substantially rigid, and therefore this type of apparatus is commonly referred to as a xe2x80x9cbrute forcexe2x80x9d or xe2x80x9csingle massxe2x80x9d system.
In many applications, it will not be unusual that there is a considerable disparity between the amounts of use of the left most motor and the right most motor. If one is energized to the substantial exclusion of the other, so called xe2x80x9cfalse Brinnellingxe2x80x9d of the motor bearings in the non-energized system will occur as a result of the vibration imparted to the bed. Lubricant may be squeezed out of the bearings as a result, and when the infrequently used system is finally energized, it may fail relatively quickly as a result of bearing failure due to xe2x80x9cfalse Brinnellingxe2x80x9d and the resulting insufficient lubrication.
To avoid these and other problems, in the commonly assigned application of Albert Musschoot entitled xe2x80x9cTwo-way Vibratory Feeder and Conveyor,xe2x80x9d now U.S. Pat. No. 5,713,457, there is proposed a bi-directional conveying system wherein a single reversible electric motor is utilized to impart vibration to a conveying surface. The direction of conveying can be altered simply by reversing the direction of rotation of the electric motor.
In this particular device, which works well for its intended purpose, the vibration inducing system including the electric motor with eccentric weights on its output shaft, produces vibrations in sizable amplitudes in all directions. Dampers are utilized to eliminate most of the vertical vibratory force component applied to the conveying surface by the single, reversible vibration inducing system, while allowing the full amplitude of the horizontal component of such force to be applied to the bed to achieve the desired conveying affect. In this system, it is necessary that a relatively large motor be employed to achieve the desired amplitude. As the desired amplitude, at least in the vertical direction, is absorbed as unnecessary to conveying and, in fact, must be absorbed in order to achieve conveying, it would seem as though a smaller motor could be used. However, when a smaller motor is employed, there is insufficient amplitude of vibratory forces in the horizontal direction to achieve the desired conveying rate. Thus, it is necessary to retain the relatively large motor, and that adds to the expense of the apparatus. This apparatus is also considered a xe2x80x9cbrute forcexe2x80x9d system.
The application of Albert Musschoot entitled xe2x80x9cTwo-way Vibratory Conveyor,xe2x80x9d now U.S. Pat. No. 6,029,796, also commonly assigned, proposes a bi-directional conveying system that may be driven by a smaller motor. A pair of horizontally acting vibration amplification systems is connected between a vibration inducing assembly and the bed, so that a comparable conveying rate is obtained with a substantially smaller motor. This apparatus, which resiliently couples the vibration inducing assembly to the bed, is commonly referred to as a xe2x80x9ctwo massxe2x80x9d system.
In the device disclosed in the ""796 patent, which works well for its intended purpose, the bed defines a linear flow path. Consequently, should a direction change be necessary, additional feeders or conveyors must be provided. Furthermore, the feeders must be modified, such as by making bias cuts in the bed, so that the objects are transported at the desired rate. This is particularly difficult in applications where a plurality of smaller objects are transported along the entire width of the bed, and where a substantially constant feed rate is desired across the width of the bed.
Other feeders and conveyors are known in which the objects are transported along a curved path on the bed. While these curved feeders have been provided as both single and two-mass systems, they have heretofore been capable only of transporting objects in a single direction along the curved flow path.